Hydraulic car-brake



t e. e h S W e e h S 2 HQ A R UB HR ZA HU w L U LA R D WY H a d 0 M o WN0. 527,743. Patented Oct 16,1894

I netorl T Witnesses: E

Attorney.

THE ucnms PETiRS 0a., PHOTQUMQ. WASHINGTON, a c.

w. L. P ITZ HUGH. HYDRAULIC GAR BRAKE.

2 sneetpsneet (No Model.)

No. 527,743. Patented Oct. 16, 1894.

Inventor.

Attorney.

Witnesses M64 inder to actuate the UNITED STATES PATENT OFFICE.

WILLIAM L. FITZHUGH, on BALTIMORE, MARYLAND.

HYDRAULIC CAR-BRAKE.

SPECIFICATION forming part of Letters Patent No. 527,743, dated October16, 1894. Application filed April 16 1894. Serial No. 5071 6' (N model-iTo all whom it may concern.-

- 1 3e it known that I, WILLIAM L. FITZHUGH, acitlzen of the UnitedStates, residing at Baltnnore, in the State of Maryland, have inventedcertain new and useful Improvements n Hydraulic Oar-Brakes, of which thefollowing 1s a specification. n

This invention relates to a car brake to be operated through the mediumof a liquid, such as water or oil. I

The object of the invention is to provide an operatlng screw connectedwith the foundatlon brake-gear of the car; a clutch mechanism connectedwith one of the axles of the car and coactlng with the said j ack-screwsa cylinder and piston for operating the clutch mechanlsm; and means forusing liquid in said cylpiston thereof, all comblned to make anoperative car-brake.

The invention is illustrated in the accompanying drawings, in which-Figure 1 is a top plan view of a carbrake mechanism embodying myinvention. Fig. 2 is a vertical longitudinal section of the same. Fig. 3is also a top'plan view in whichsome of the parts shown in Fig. 1 areomitted. Fig. 4 is a detail view of the gearing for operating thejack-screw. Fig. 5 is a detail view of the mechanism for returning thejack-screw to its normal position after the brakes have been applied.Fig. 6 is a modification of the device shown in Fig. 5.

The letters, A, A, designate the car-axles; B, the wheels; 0, thebrake-shoes D, the brakebeams; E, E, the rods, and, F, F, the chains.These parts, commencing with the brakeshoes, comprise the ordinaryfoundation brake-gear of a car, and may be constructed in various ways.By drawing on the chains, F, the brake-shoes will be pressed against therim of the wheels.

The lever,'G, pivoted at, a, is connected with the chains, F, F, in suchmanner as to draw them. In the present instance this lever is a doublebell-crank 0r T-shaped lever. The two arms, I), b, of this lever extendfrom the pivot, a,;in opposite directions, and one chain, F, connectsone arm, I), with the end of the rod, E, .while another chain, F,connects the opposite arm also with the same rod. Thus the two chains,F, F, connected as described have a V-form. The lever, G, has anactuating arm, 0, by which it is turned on its pivot,

a. By this arrangement if the actuating arm,

ing internal screw-threads which fit and serve as a nut on the saidscrew, H.

A yoke-hanger, J, has its two arms pendent from the bottom of the car,and the jackscrew, H, passes horizontally through both arms thereof,while the screw-threaded pinion, I, is on the screw and 'fits snuglybetween the said two arms of the hanger. Thus the pinion, I, can revolvebut cannot move laterally because of said two arms. Consequently whenthe pinion does revolve the operating screw is moved endwise laterallythrough'the pinion, one way or the other, according to the direction ofrevolution of the pinion.

The axle, A, carries a loose gear-wheel, K, which is always in gear withthe pinion, I. When not employed to apply the brakes the axle, A, willturn-without causing the gearwheel, K, to turn with it. w

A clutch device is employed on the axle, A, to hold the wheel, K, rigidwith respect to the axle and cause it to revolve when'it is desired toapply the brakes. This clutch device comprises a disk, e, fixed rigid tothe axle at one side of the loose gear-wheel, K, and another disk, 6,also on the axle at the opposite side of the said wheel. This latterdisk, c, has a collar with a circumferential groove, f, and is securedon the axle by means of the well-known groove and spline, g, so as to bemovable longitudinally'on the axle but compelled to revolve with theaxle. The fixed disk, '6, on one side of the wheel, K, and

the movable disk, e, on the other constitute the clutch.

A lever, L, is pivoted at, h, and has a yoke- 7,

end or bifurcated end, '2', to spanthe groove, f. Each terminal of thesaid bifurcation has a pin, j, to engage in the groove. By moving thelever, L, the disk, e, of the clutch is brought hard up against theloose wheel, K, and thereby this wheel is caused to revolve.

A liquid tank or reservoir, M, communicates with the train-pipe, N, bymeans of a passage, m, which has a checlcvalve, m, to allow liquid fromthe tank to run into the train-pipe but to close the passage and preventany back flow or return of the liquid. This tank is filled with theliquid through an opening, a, in the top and inthe car-floor.

A main cylinder, 0, connects with the trainpipe by means of a branchpipe, 0, passing through one of its heads, 19, and through this branchpipe liquid from the train-pipe enters and fills the cylinder. Thecylinder has a piston, P, and a piston-rod, P, is connected with afoot-lever, g, by a link, 19', and this foot-lever is the means by whichthe piston is actuated to force the liquid out of the cylinder and intothe train-pipe under pressure to apply the brakes. A spiral spring, 0",within the cylinder returns the piston to its normal position when thepressure on the piston-rod is removed. A hand-lever, 3, may take theplace of the foot-lever if desired.

An operating cylinder, T, is connected with the train-pipe by abranch-pipe, 25, opening through the head, L6, and is provided with apiston, U, having a piston-rod, U, which is attached to the yoke-lever,L, by a link, 4). When the liquid is forced through the trainpipe underpressure from the main cylinder, 0, said liquid acts on the piston, U,and causes it to operate the yoke-lever, L, which will force theclutch-disk, 6', against the loosewheel, K, causing it to revolve withthe axle. The pinion, I, is thereby caused to revolve and move theoperating screw endwise laterally in the desired direction and pull orpush, as the case may be, on the bell-crank lever, G, and apply thebrakes.

To return the operating screw, H, to its normal position and release thebrakes it is necessary to reverse the rotation of the pinion, I. This isdone by a coil spring, to, on the side of the pinion, and which has oneend fastened to the pinion by a pin, and the other end fastened to across-bar, w, on the yoke-hanger, J. WVhen the brakes are applied thisspring is to wind up, and its reactive tension will cause the pinion torotate in a reverse direction and return the operating screw to itsoriginal position and release the brakes.

In Fig. 6 is shown a modification of the means for reversing therotation of the pinion, I, and releasing the brakes. In this instancethe pinion, I, has a hub or winding drum, I, and a cord, .2, is attachedat one end to the pinion and at the other end to a spiral spring, a,which latter may be connected with some suitable part of the carframe orgear. This cord winds around the hub or drum, 1, of the pinion one wayor the other when the brakes are applied and the reactive tension of thespring, a, will cause said pinion to rotate in a reverse direction andreturn the operating screw to its normal position and release thebrakes.

The train pipe has at each end of the cara pipe coupling, Y, forattachment to the trainpipe of a next adjoining car, and a cock, Y, forclosing the pipe and preventing the escape of fluid when the couplingsare detached.

WVhile I have described my invention asit is specifically shown in thedrawings, it is obvious that certain details of construction may bevaried without departing from my invention as hereinafter claimed.

Having thus described my invention,what I claim as new, and desire tosecure by Letters Patent, isi 1. In a fluid pressure air brake, thecombination of an operating screw connected with the brake rod of thecar; a pinion having a threaded hub to turn on the said screw; a loosewheel on the car axle meshing with the said pinion; a clutch mechanismconnected with the axle and coacting with the said loose wheel; andmeans for operating the clutch mechanism.

2. The combination of an operating screw connected with the foundationbrake-gear of of a car; a pinion having internal screwthreads which fitand serve as a nut on the said screw; a loose gear wheel on the car-axlewhich gears with the said pinion; a clutch mechanism to bind the loosewheel against the car axle and cause it to revolve therewith; a cylinderand piston for operating the clutch mechanism; and means for usingliquid in said cylinder to actuate the piston thereof.

3; The combination of an operating screw connected with the brake rod ofacar; a pinion having a threaded hub to turn on the said screw; a loosewheel on the car-axle meshing with the said pinion; a liquid tank orreservoir; a main cylinder connected with the train-pipe and having apiston to force liquid.

through said pipe under pressure; clutch mechanism coacting with thesaid loose wheel; an operating cylinder having a piston which operatesthe clutch mechanism; and means for moving the main-cylinder piston toforce liquid under pressure through the train-pipe to actuate the pistonin the operating cylinder.

4:. The combination of an operating screw connected with the foundationbrake-gear of a car; an internally screw-threaded pinion for moving thesaid screw; a loose gear-wheel and a rigid disk, e, on the car axle atone side of the wheel and a movable disk on the opposite side; a lever,L, acting to move the disk, 6', hard up against the loose wheel andcause said wheel and the pinion to revolve; a cylinder and piston foroperating the lever; and means for using the liquid'in said cylinder toactuate the piston thereof.

In testimony whereof I atlix my signature in the presence of twowitnesses:

WILLIAM L. FITZHUGH.

Witnesses:

CHAS. B. MANN, CHARLES B. MANN, J r.

IIO

